15E.4

Question 1

what are the limitations of HPLC and GC

Answer 1

they are not good at identifying the substances

Question 2

why is HPLC and GC considered not good at identifying the substances

Answer 2

1. hard to control all the variables (solvent, pressure, temperature)
2. different substances may have the same retention time

Question 3

what are two areas that the result of HPLC and GC need to be exactly correct

Answer 3

1. in providing forensic evidence
2. in detecting banned drugs in sports women and sportsmen and race horses
3. detecting explosives in airport baggage
4. analysis of pollutants in the environment
5. space probes in other planets

(FIRST 2 MOST IMPORTANT)

Question 4

since the results of HPLC and GC are with doubt what do we use with them

Answer 4

we use mass spectrometry

Question 5

what is the abbreviation when techniques of HPLC/GC and MS combine

Answer 5

HPLC-MS GC-MS

Question 6

how does GC-MS work

Answer 6

stage 1: the mixture is injected into GC
stage 2: each component has different retention time, so they emerge at different times
stage3: one at a time, each component enters the MS
stage 4: each component would have its mass spectrum displayed
stage 5: the m/z value and relative abundances of components are compared with database of known substance
stage 6: then a match is found, and the component is identified

Question 7

why did some athletes test positive for nandrolone when they did not take it

Answer 7

1. some nutritional supplements that are allowed had nandrolone in them
2. permitted dietary supplements combined with exercise increases the concentration of nandrolone in the blood

Question 8

facts about nandrolone

Answer 8

page 141 (ask miss if we need to know)